Total Mileage Between Fill-Ups

Hello everybody I'm new to this forum and I must say I'm so happy I got a prius. Anyways I really do believe I learned to drive in this car even though I've been driving for the past 9+ years. Currently my car has 16100+ mile on it and since the 5k mile service I haven't reset the cars MPG tracker and it currently reads 57.7 mpg. My average fill up is between 540-570 miles 9.2-9.8 gallons. My best tank lasted me 610 mile on
9.7 gallons. I drive on the Highway 70% of the time at an average speed of 60 mph and I stick to the slow lane so I can relax and laugh at everybody race right past me.

 

That sounds like winter mileage here in NYS. I'm guessing mountains were involved.

 

A 2007 Prius here and I average about 450 - 490 usually. I have broken 500 a few times, and high has been about 520. I tend to refill when its blinking (stop within 30 miles or less). The range is dependent on the refill, and sadly in NJ, we cant refuel our own cars (I do still at my local station), but i knwo when i rim it, i can go for 500.

Robert

 

I NEVER rim it (which I guess means putting more in after the click). I think this tank will be low due to it. It is down to 2 bips now and I have 375 miles on the tank - and the average is 48.9 so far. Last time I filled it, it only took 8 gallons.

 

yea haha up and down, up and down
100deg temps
A/C set at 73deg on "auto"
car was fully loaded
2 niece
1 nepwhew
1 brother
and a trunk full of our junk

 

I have a used 2007 Prius, I have read many of the posts regarding gas mileage, I changed the tire pressure to 40psi front and 38psi in the rear, my average on the display is between 42/46 most of the time, this fill up I waited till it started to blink indicating I was low on fuel, I did 482.2 miles and it took 11.5 gallons filling it to the brim, like I always do and I'm still averaging 42.014 mpg doing the calcuation the old fashioned way, by taking out my calculator and doing the division and not relying on what the onboard screen is showing me, and that is so much different than what I am really getting. My total mileage since I own the car is 1,197.6 miles and I've put in 28.194 gallons of gas which gives me a total of 42.477 mpg.

MY QUESTION IS...WHY CAN'T I GET MORE THAN 42 MPG ON THIS CAR? This is all city/highway driving, I even took the car back to the dealership and they told me there is nothing wrong with the car. I live in Nevada where the temperatures have been hot, with the a/c running all the time. Could this be the problem? I would like to hear from anyone that does the mpg check using the old fashioned method of using a calculator dividing total mileage by gallons and tell me what you are averaging.

 

in the 3+months i had my 08 touring, i havent quite mustered up 45+mpg on the old fashioned calculation...but the MFD was reading 47ish

i too avg about 42mpg on combined driving but mostly hwy @ 70+mph

 

As has been stated here many times, heat and short trips will kill your mpg. Heat because the AC will suck the juice out of your traction battery, and also because the battery looses efficiency the hotter/colder it gets. Short trips because the car is never in its most efficient state.

 

Earning 52.7 mpg and over 500 mi per tank consistently for 30,600 mi on a 2007 Touring. Slightly lower in winter, slightly higher in summer.

 

Hit 508 miles last week before I filled up with 9.5 gallons. Love the hot, summer weather. Once ran out of gas at 546 miles in June though...not good!

 

Oil Change? synthic helps, really does. i gained 3mpg. try running your a/c at 76-78 on full blast. i tried that 74 didnt gain. i found out high fan output with a higher temp works better.
drive it more

btw i do the old fashion way.

 

I think this is my first tank that is victim to the shrinking/expanding gas tank. I have read much about this so I am not worried. It just goes to show you that you need to rely on the gas gauge - not the miles driven - when deciding when to fill up. Today I hit 1 pip on the way to work, so I stopped on the way home and refilled. I got 10.08 into the tank this time. I had driven 379 miles on the tank - averaging 48.9 according to the MFD.

 

Isn't the displayed MPG on the MFD accumulated? We got down to the first bar today and had no blink and put in 11.01 with out a spillover.. Sounded like I could have gone further but pump wouldn't continue, so I might have found a consistant place to fill.

I figure my mileage the old way too, and we get between 40 to 46 depending on which roads we travel (speed zone), speed -duration of air conditioning, side winds etc.

It might depend on who fills the tank, my wife settles for fill ups on the first notch at the pump. She will get inflated mpg if she fills after I do. I have noticed that speed of fill varies from station to station pump to pump, I go for slowest setting, when I hit auto shut off, I try to squeeze it in slow and listen for the gurgle.

 

To my knowledge the MPG on the display is reset after each fillup. I keep a running lifetime MPG in a spreadsheet at home. That is one thing I wish they would add to the MFD - 2 displays for MPG - tank and lifetime. Not to mention that other hyrbrid, but the HCH has muliple MPG displays

 

After much reading of the posts regarding MPG on any PRIUS I believe that everyone is under the false prestense that these cars are getting higher gas mileage than you think. The MFD is only a questimation on what you're actually getting. I have noticed that YES we can get approx 450 to 480 miles on a tank, of course if you only put in 8.0 gallons, or 9.2 gallons, and do the math you will get those high MPG. Even seeing on the MFD display showing you 58 or 52 or 53...when u do the math regardless of how much gas you put, it doesn't add up to the MFD display. I would like to see everyone wait till the last PIP lights, and just starts to blink, and then fill it up to the brim where you can see the gas on top, get in at least 11 gallons or more, then do the math, divide the the mileage by the gallons put in and then you guys let me know the true gas mileage per gallon. On my last fill up, the nozzle stopped at 8 gallons, I was able to squeeze in another 3.5 gallons which came to 11.5 gallons and I did 482.2 miles on 11.5 gallons gas = 42.104 mpg and the MFD was showing me 45 to 47 which is a big difference in the true mileage. Now if I stopped pumping at that 8 gallons and did the math the 482.2 divided by the 8 gallons would have showed me that I was getting 60.275 mpg. BIG DIFFERENCE HUH?

 

agree^ doing it the old fashion way I'm always around 40-42mpg LOL

 

Anywhere between 650-800 miles in the summer. Winter subtract 200 miles from that range.

Wayne

 

Summer: Around 515 mi. -- 2 pips @ 65 mpg

 

In my 6 months of ownership, the gap between calculated mpg & MFD-shown mpg has shrunk dramatically.

In the beginning I saw a 4-5 mpg difference. Now, it's just about right on.

It may relate to numerous factors -- loosening of the bladder, warmer temp, etc. We'll see how it turns out next winter.

 

Problem with that is that some folks can't or won't refuel immediately and will end up running dry. Not a good thing -- there are numerous threads on the consequences.

Then when you try to squeeze in more, as you suggest, you risk overfilling and saturating the charcoal cannister. Also not a good thing -- see this for the consequences.

I understand what you're trying to do. Here is a better way, perhaps: I use a spreadsheet that tracks calculated and MFD mileages, with per-tank differences weighted based on how many miles were driven with that tank. I then average the weighted differences for a cumulative difference, currently at 2.6%.

Here's the spreadsheet minus the last two tanks: